Pallet disassembling method and apparatus

ABSTRACT

Method for disassembling a wooden pallet. A vertically movable carrier is provided with a pair of horizontal tines which are insertable in the openings formed between the slats and ribs of a pallet. A plurality of upper and lower breaker members are mounted above and below the tines so as to register with the portions of the ribs located between adjacent slats. Actuating means is provided to move the tines up and down so that the slats of a pallet carried thereon are moved across the plane of the ends of the breaker members to cause the slats and ribs to be pulled apart and separated for salvage.

This is a division of application Ser. No. 479,894, filed June 17, 1974,now U.S. Pat. No. 3,916,498.

BACKGROUND OF THE INVENTION

This invention relates to cargo carrying wooden pallets, and inparticular relates to the disassembly of such pallets for purposes ofrecovery and reuse of the slats and ribs that are used in theirconstruction.

Cargo carrying pallets that are constructed of wooden slats and ribs arecommonly used for handling and carrying a wide range of goods and cargo.Boxes of the cargo typically are loaded on the pallets and a materialhandling vehicle, such as a forklift truck, is then used to pick up andmove the loaded pallet. The forklift trucks are adapted to move thepallets into and from truck trailers and railroad cars, and also tomove, stack and position the loaded pallets at loading docks, warehousesand other storage areas.

Pallets of the foregoing character oftentimes are damaged and renderedunsafe or unusable when the slats and ribs are broken or cracked duringuse. It is then necessary to replace the pallets. However, because ofthe relatively high cost of lumber, eg., the wooden ribs and slats cancost as much as fifty cents each, it is desirable to break apart ordisassemble the pallets so that the unbroken slats and ribs can besalvaged for rebuilding into additional pallats. Heretofore, it has beenexceedingly difficult to break such pallets apart, especially where theyare assembled by the use of helical or twisted nails. In the pastworkers have used crowbars or other similar tools to manually break thepallets apart, but this is slow and expensive in view of the high costof labor. In many cases broken or damaged pallets have merely beendiscarded without attempting to salvage the usable slats and ribs.Accordingly, the need has been recognized for a means which will make itfeasible to salvage the usable lumber from broken or damaged pallets.

OBJECTS AND SUMMARY OF THE INVENTION

It is a general object of the invention to provide a method and torapidly and easily disassemble cargo carrying pallets for salvaging thelumber therefrom.

Another object is to provide method of the character described by whicha single operator can load a pallet, manipulate the controls foractuation to separate the slats from the ribs of the pallet, and removethe separated parts in a relatively short cycle time.

Another object is to provide a method of the character described whichis capable of disassembling pallets with a wide range of overall sizeand of varying board sizes and spacing, and further which is capable ofdisassembling pallets of either two-way or four-way entry design.

Another object is to provide a method of the character described inwhich pallets are loaded onto a pair of tines that are adapted to beelevated and lowered with respect to upper and lower breaker barsmounted on a frame, and in which certain of the breaker bars are adaptedto be adjustably positioned so as to register with the pallet ribs atvariable spacing between the slats.

The invention is characterized in providing a pallet carrier mounted formovement on a frame. The carrier includes a pair of elongate tines whichare adapted to be positioned within the spacing or openings formedbetween the ribs and slats of each pallet. Breaker members are mountedon the frame on opposite sides of the tines in register with the ribs ofa pallet which is mounted on the carrier. Certain of the breaker membersare adapted to be adjustably positioned along the ribs so as to registerwith a variable spacing between the slats which are fastened to theribs. Actuating means is provided for moving the carrier relative to thebreaker members whereby the slats are pulled and separated from the ribsas the tines are moved across the plane of the edges of the breakermembers. The separated slats and ribs are then removed and anotherpallet is mounted on the tines for disassembly in the manner described.

Additional objects and features of the invention will appear from thefollowing description in which the preferred embodiment has been setforth in detail in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevational view of apparatus of the invention;

FIG. 2 is a perspective view of a pallet of the type that isdisassembled by the apparatus of FIG. 1;

FIG. 3 is an end elevational view of the apparatus of FIG. 1; and

FIG. 4 is a sectional view taken along the line 4--4 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawing FIG. 1 illustrates generally at 10 apparatus constructedin accordance with the invention which is used for disassembling ordismantling cargo carrying wooden pallets, of which a typical pallet 11is illustrated in FIG. 2. The exemplary pallet 11 is characterized inhaving a plurality of flat, spaced-apart parallel wooden slats 12, 13which are fastened to and extend laterally across three upright, spacedapart parallel wooden ribs 14-16. The slats and ribs define a pair ofopenings 17, 18 into which the two blades of a forklift truck, notshown, can be inserted and removed from either end of the pallet. Thepallet 11 is of four-way, design, i.e. the lower edges of the three ribsare formed with cut-outs 19, 20 of a width slightly greater than thewidth of the forklift blades so that such blades can be inserted intothese openings from either side of the pallet. Thus, a forklift truckcan pick up the four-way pallet 11 from any one of its sides or ends.The invention also can be used in disassembling pallets of two-waydesign without the cut-outs where entry of the forklift blades is madeonly from the two ends of the pallet. The invention furthermore can beused for disassembling pallets of different boad sizes and spacing, andfor disassembling pallets of a range of overall size.

Apparatus 10 includes a frame 22 which comprises a base 23 upon which anupstanding mast 24 is mounted. The base is formed of box-section tubularmembers 26 which are welded together in a generally rectangularconfiguration. The mast is welded to these tubular members and isreinforced by means of pairs of cross braces 27, 28. The base can beanchored to a suitable foundation or floor, or alternatively can beunanchored to permit it to be easily transported between work locations.

The mast 24 comprises a pair of upstanding channels 29, 30 secured attheir lower ends to the tubular members of base 23. The inwardly facingsides of the channels are formed with vertically extending recessedguide tracks 32, 33.

A pallet carrier 34 is mounted for vertical movement with the tracks 32,33. The pallet carrier includes a truck 36 which extends between the twochannels and which carries at each of its opposite sides a verticallyspaced pair of wheels 37, 38. The wheels are adapted to roll within theguide tracks as the carrier is moved up and down. The carrier 34 furtherincludes pairs of horizontally extending, laterally spaced-apartelongate tines 39, 40 which are mounted at their inner ends to thetruck. The tines are spaced apart a sufficient dimension which permitsthe pallet 11 of FIG. 2 to be placed on the carrier structure with thetines inserted in the two openings 17, 18 formed between the ribs andslats. A pair of downwardly-facing elongate spacer channels 42, 43 aresecured by suitable means such as welding to the upper surfaces ofrespective tines 39, 40. The lateral width of each spacer channel iscommensurate generally with the inner width of each pallet opening so asto properly center the pallet on the tines.

Actuating means is provided to move the pallet carrier, and thisactuating means includes an extensible hydraulic cylinder 44 having itslower, head end secured to base 23 and with its rod end secured to theupper end of truck 36. The cylinder is extended and retracted to raiseand lower the carrier by means of pressurized hydraulic fluid. A sourceof pressurized fluid is supplied from hydraulic pump 46 which is drivenfrom a suitable motor 47, such as an AC electric motor. Supply andreturn fluid conduits 48, 49 extend from the pump to a suitable manuallyoperated two-way flow control valve 51 which is adapted to directpressurized fluid into either of the conduits 52, 53 to the head or rodends of actuator 44, and to direct return fluid from the actuator backto pump 46. While the control valve 51 is shown as being positionedadjacent the motor and pump, this valve could also be located at theopposite end of the frame adjacent the loading end of the tines toafford convenient access for the operator to manipulate the controlvalve without having to shift his position for loading pallets onto thetines.

A lower sub-frame assembly 54 extends forwardly from the mast at alocation below the pair of tines 39, 40. This sub-frame assemblyincludes a pair of spaced-apart side rails 56, 57 which are secured atopposite ends to a pair of front and rear rails 58, 59. Preferably theserails are comprised of box section tubing. The rear rail 59 is attachedto the forward face of mast 24, and the two side rails are supportedabove the frame by means of a pair of support columns 61, 62.

A plurality of lower breaker members 63-67 are mounted on sub-frameassembly 54. These breaker members comprise elongate flat bars whichextend upwardly in a direction along opposite sides of the tines inregister with the bottom edges of the ribs of a pallet which ispositioned on the tines, as shown in FIG. 4. The breaker members 63, 65and 67 are carried by means of three cross-beams 68, 69 and 70. Thecross beams are positioned along the upper edges of the two side rails56, 57, and a pair of smaller box section tubular rails 72, 73 extendacross the outboard ends of the cross beams in vertical register withthe side rails.

The inner group of three laterally spaced breaker members 63 are securedat their lower ends to the cross beam 68 which is affixed at itsoutboard ends to the side rails by suitable means such as welding. Thesecond group of three laterally spaced breaker members 65 are secured attheir lower ends to the center cross beam 69 which is free to slidealong the spacing between the pairs of rails. The outboard ends ofcenter cross beam 69 project outwardly from the side rails to formhandles which permit the operator to adjust the lengthwise position ofthis cross beam so that the breaker members which it carrys can be spotpositioned to register with any variation in the spacing between theslats of an overlying pallet. The third group of breaker members 67 ismounted to the cross beam 70 which is secured at its outboard ends tothe side rails by suitable means such as welding. Additionally, the twopairs of breaker members 64 and 66 are fixedly secured to respectiveinboard sides of the side rails, and the upper edges of these latterbreaker members terminate in a plane common with the terminal ends ofthe breaker members 63 and 67 carried by the fixed cross beams. As bestshown in the side view of FIG. 1 the stationary breaker members extendupwardly a greater distance than the breaker members 65 carried byadjustable cross beam 69. This permits the ends of the stationarymembers to contact the recesses 19, 20 in the ribs of pallet 11 at thesame time that the ends of adjustable members 65 contact the bottomedges of these ribs. As shown in FIG. 4 the breaker members arespaced-apart so as to register with the three ribs 14-16 and the widthof each breaker member is sufficiently long so as to accommodate palletswith a range of rib spacing and size.

An upper sub-frame assembly 76 is positioned above the pair of tines 39,40. This sub-frame assembly includes pairs of vertically spaced apartupper and lower box section tubular rails 77, 78 and 79, 80 which aresecured to and extend between four upright corner posts 82-85. Assembly76 is braced by means of box section tubular rails 87, 88 which aresecured between the upper ends of the corner posts, by a front rail 89awhich extends across the ends of the two front corner posts, and by arail 89b which extends across the upper ends of the channels 29, 30. Twopairs of vertical support posts 86a, 86b are mounted on opposite sidesbetween the rails 77, 87, 79, 88.

A plurality of upper breaker members 90, 91 and 92 are mounted onrespective cross beams 93, 94 and 95. These members extend downwardly ina direction along opposite sides of the tines in register with the upperside edges of the three pallet ribs. The first group of three laterallyspaced breaker members 90 is mounted to the cross beam 93 which issecured at its outboard ends to the opposite pairs of rails by meanssuch as welding. A second group to three laterally spaced breakermembers 91 is mounted to the central cross beam 91 which is slidablymounted between the opposite pairs of rails 77-80. The outboard ends ofcross beam 91 project outwardly from the sides of the rails to providehandles for an operator to manually adjust the position of the crossbeam so that its breaker members register with variable spacing betweenthe pallet slats. The third group of three laterally spaced breakermembers 92 is mounted on cross beam 95 which is also slidably mounted atits outboard ends of beam 92 serve as handles for manually adjusting itsposition. The lower ends of the breaker members carried by the threeupper cross beams lie in a common plane so as to jointly contact theupper edges of the three ribs for separation of the upper slats.

Apparatus 10 of the invention can also be adapted for the disassembly ofpallets that are of two-way entry design, i.e. pallets in which thecut-outs 19, 20 as shown in FIG. 2 are not formed in the ribs. For suchan adaptation all lower breaker members 63-67 are formed with theirdistal ends lying in a common plane so that, as the tines and palletmove downwardly, the ends of these breaker members jointly contact thelower edges of the pallet ribs for removal of the lower slats.

The use and operation of apparatus 10 will be described in connectionwith the disassembly of wooden pallets in which certain of the slats orribs are broken or cracked or are otherwise damaged. For conditioningthe pallets prior to disassembly, stacks of the pallets are sprinkledwith water and permitted to soak for a number of hours, such asovernight. This soaking causes the slats and ribs to become moreflexible so that disassembly is facilitated.

With the tines of the apparatus positioned midway between the upper andlower breaker members, as illustrated in FIGS. 1 and 2, the operatorloads a pallet by pushing it onto the tines and channels 42, 43 whichare inserted through the pallet openings 17, 18 as shown in FIG. 3. Theposition of the pallet is manually adjusted both lengthwise andlaterally of the tines so that the first group of breaker members 90carried on stationary beam 93 are in register with the upper edges ofthe ribs at the spacing between the first and second slats 12a and 12b.The operator then moves to either side of the apparatus and grasps theouter end projections of central beam 94 and moves it until its breakermembers 91 register with the ribs at the spacing between the slats 12band 12c. Similarly the front beam 95 is adjusted until its breakermembers 92 register with the ribs at the spacing between the pair ofslats 12d and 12e.

With motor 47 energized and driving pump 46 to supply a source ofpressurized hydraulic fluid, the operator manipulates valve 51 to directthe fluid through conduit 52 to the head end of cylinder 44. Thecylinder is thereby caused to extend and move truck 36 upwardly alongthe mast. The truck in turn carries the tines and pallet upwardly untilthe distal ends of the upper breaker members contact the upper edges ofthe three ribs, which are thereby blocked in their upward travel.Continued movement of the tines past the plane of the distal ends of thebreaker members carries the slats upwardly so that they are pulled orotherwise disassembled from the ribs, and this is normally accompaniedby the fastening nails being pulled from the ribs at the same time.

To disassemble the lower slats, the operator adjustably positions, asrequired, the pallet lengthwise of the tine so that the fixed breakermembers 63, 64 and 66, 67 are in register with the bottom edges of theribs in the regions of the cut-out portions 19, 20. As required, theoperator adjustably positions the central cross beam 69 so that thebreaker members 65 which it carries are in register with the ribs at thespacing between the slats 13b and 13c.

The operator then reversely manipulates valve 51 to direct pressurizedfluid through conduit 53 into the rod end of the actuator, which therebyretracts and moves truck 36 downwardly along the mast. This causes thetines and pallet to move downwardly until the distal ends of the lowerbreaker members contact the lower edges of the ribs, which are blockedin their downward movement. Continued movement of the tines carries theslats below the plane of the distal ends of the lower breaker membersand this causes the lower slats to be pulled or otherwise disassembledfrom the ribs. The operator then manually removes the separated slatsand ribs by reaching through the end and sides of the apparatus. Theusable lumber is then stacked for salvage and subsequent assembly intoadditional pallets, and the broken or cracked lumber is segregated anddiscarded. The control valve 51 is then manipulated to return the tinesto their midposition between the breaker members. Additional pallets arethen loaded onto the tines and disassembled by repeating the foregoingprocedures.

While the foregoing embodiments are at present considered to bepreferred it is understood that numerous variations and modificationsmay be made therein by those skilled in the art and it is intended tocover in the appended claims all such variations and modifications asfall within the true spirit and scope of the invention.

We claim:
 1. A method for disassembling cargo carrying pallets which areconstructed of a plurality of generally parallel, spaced-apart slatsthat are fastened to and extend laterally across the top and bottomedges of a plurality of generally parallel, spaced-apart ribs, themethod employing horizontally extending tine means which are positionedbetween a plurality of upper breaker mmebers and a plurality of lowerbreaker members, the method including the steps of inserting a palletonto the tine means with the latter being disposed generally parallelwith the ribs and between the top and bottom slats, with the lowerbreaker members positioned in register with portions of the ribs whichare exposed between the slats, moving the tine means downwardly againstthe slats while holding the lower breaker members stationary to causethe bottom slats to be separated from the ribs, positioning the upperbreaker members in register with portions of the ribs which are exposedbetween the top slats, and moving the tine means upwardly against thetop slats while holding the upper breaker members stationary to causethe top slats to be separated from the ribs.